4D Variational assimilation of wake flow with a dynamics error model

Duration: 21 mins 25 secs

Share this media item:

Embed this media item:

<iframe width="_width_" height="_height_" src="https://sms.cam.ac.uk/media/3237326/embed" frameborder="0" scrolling="no" allowfullscreen></iframe>

Choose size:

About this item

Available Formats

About this item

4D Variational assimilation of wake flow with a dynamics error model's image

Description:	Presentation by Pranav Chandramouli (TU Delft) at online meeting on 'Data Assimilation in Fluid Mechanics', organised by the UK Fluids Network Special Interest Group 'Flow instability, modelling and control', 27th May 2020.


Created:	2020-06-16 10:22
Collection:	Data Assimilation in Fluid Mechanics - 1st online meeting of UKFN SIG 'Flow instability, modelling and control'
Publisher:	University of Cambridge
Copyright:	Pranav Chandramouli
Language:	eng (English)


Abstract:	A novel variational assimilation technique (4D-Var) is presented to reconstruct time resolved incompressible turbulent flows from measurements on two orthogonal 2D planes. The proposed technique incorporates an error term associated to the flow dynamics using concepts borrowed from large-eddy simulation and stochastic turbulence models. A reconstruction algorithm, termed snapshot optimisation (SO), is also presented for recreating 3D data from two 2D orthogonal planes of data obtained over a long-period of time. The proposed 4D-Var algorithm is successfully applied on a 3D turbulent wake flow in the transitional regime without specifying the obstacle geometry. The algorithm is analysed on synthetic data emulating large-scale experimental PIV observations reconstructed using the SO algorithm.

Abstract:

A novel variational assimilation technique (4D-Var) is presented to reconstruct time resolved incompressible turbulent flows from measurements on two orthogonal 2D planes. The proposed technique incorporates an error term associated to the flow dynamics using concepts borrowed from large-eddy simulation and stochastic turbulence models. A reconstruction algorithm, termed snapshot optimisation (SO), is also presented for recreating 3D data from two 2D orthogonal planes of data obtained over a long-period of time. The proposed 4D-Var algorithm is successfully applied on a 3D turbulent wake flow in the transitional regime without specifying the obstacle geometry. The algorithm is analysed on synthetic data emulating large-scale experimental PIV observations reconstructed using the SO algorithm.

Available Formats

Format	Quality	Bitrate	Size
MPEG-4 Video	1280x720	1.36 Mbits/sec	218.69 MB	View	Download
MPEG-4 Video	640x360	442.85 kbits/sec	69.47 MB	View	Download
WebM	1280x720	659.5 kbits/sec	103.53 MB	View	Download
WebM	640x360	220.32 kbits/sec	34.59 MB	View	Download
iPod Video	480x360	475.07 kbits/sec	74.52 MB	View	Download
MP3	44100 Hz	249.9 kbits/sec	39.47 MB	Listen	Download
Auto *	(Allows browser to choose a format it supports)